Remote control system



Feb- 9, 1937' n.1. STEWART REKOTE CONTROL SYISTEM 2 Sheets-Sheet 1 FiledDec. 15, 1933 INVENToR .Duncan J. Stewat ,Tn mw rUL LA www Us:

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Dn In /23 ATTORNEYS Fell 9 1937- D. J. sTEwART nanou: coNTRoL'sYsTEM 2sheets-sheet 2 yFired Dec. 15. 193s A TSN b SSS ATTORNEYS Patented Feb.9, y1937 accanto 2.06am n PATENT ori-lcs y f J REMOTE CONTROL SYSTEM ADuncan J. Stewart, Rockford, Ill., assigner to f /Howard D. Colman,Rockford, Ill.

Appunti December 15, 1933, serial No. 102,434

1o claims.

The invention pertains to a`system oi' remote control and involves thetransmission oi' ai, signal from a remote point, for example, from amotor4 vehicle to control a power driven mechanism such as anelectrically driven door operator by means responsive to the transmittedsignal.

One object of my invention is to provide a control system 4oi' thecharacter indicated, which is simple in construction, so as tobe/capable oi' being supplied at Ia relatively low cost, andvvwhichv isreliable in operation. l

Another object is to provide a control system -of the aforesaidcharacter, including a sensitive detector element responsive to signalstransmitted from a remote'point and operable to perform the therebyavoiding unintendedY or ac cidental operation. f

Thek accompanying drawings illustrater` the invention in a preferredembodiment, applied to the control of a garage door operator andutilizing radiant energy signals of a preconcerted character transmittedfrom amtor vehicle. It should be understood, however, that the inventionis susceptible of wide application and in its broader aspects, is notlimited to the use of radio signals. In the drawings: l

rFigure 1 is a perspective view illustrating schematically a powerdriven garage door operator adapted to be ,controlled by means of asignal transmitted from a motor vehicle shown in approaching relation toaV garage.`

Fig. 2 illustrates a time chart showing the sequential operation ofvarious parts of the control mechanism with respect to a transmitted,signal cfa preconcerted character.

Fig. 3 is a schematic view partially in perspective showing thetransmitting and receiving mechanismslwith an electrically driven dooroperator connected with the receiver, the door operator being shownschematically.

In one aspect, my invention is an improvement upon the selectivesignalling apparatus of the ,patent to Howard i). Colman, No. 1,760,479,dated May 27, 1930. Generally stated, the improvement resides in thesimplicationlof the transmitting and signal responsive controlmechanisms. Thus, according Ytomy invention, the transmitter may be ofa' slmplled character, involving merely the use of amanually operableswitch in place of a mechanically timed sending mechanism; and thecontrol mechanism operating in response to theI received signal involvesa simple motor driven device whose operation is initiated upon thereceipt yof -the initial impulse'of ythe transmitted signal, butdepends, for the proper completion of the rcycle and the performance ofthe intended operation, upon the receipt of a complete signal ofpreconcerted character. y i

Referring now to the drawings, the motor I vehicle (Fig. 1) is equippedwith a signal transmitting mechanism including a sending antenna I whichmaybe mounted beneath the body 'of the vehicle in the manner disclosedin my prior Patent No. 1,792,193, dated February 10, 1931. In thedriveway leading to the garage is a receiving antenna 5 leading to asignal 'responsive control mechanism within the garage and governing anelectrically driven door operator shown diagrammatically at '6. I Asshown at the left of Fig. 3, the sending an- ,tenna l is connected withan induction coil 1, whichin turn is in circuit with a car battery 8 anda` manually operable switch 9 on the instrument panel of the vehicle,the general arrangement being the same as shown inthe said Colman PatentNo, 1,760,479, except for the use of the manually operable switchv 9 inplace of a mechanically operated switch. Accordingly, in the presentinstance, the character of the signal transmitted is determined by themanner in which the switch 9 is operated by the driver of the vehicle;`It will be understood however, that instead of manual operation a simplemechanical operator under manual control may be employed. The powerdriven door operator, which may be of the type disclosed in the saidColman patent, in-

cludes ,a reversible electric motor I (shownat the right in Fig. 3) foractuating the door or doors as the case may be. Electric power issupplied to this motor under the control of a main switch Il interposedin one side l2 oi' a power line, of which I3 designates the other side.

The receiver for the transmitted signals forms perse no part of thisinvention, being substan- `tially the same as in said Colman patent. Asshown, it comprises in addition to the receiving antenna a radiofrequency coil I4 grounded at llli. i6 designates generally a vacuumdetector tube'of the three element type, comprising a grid I1, a plateI8, and a filament i9.

' The filament is adapted to be heated continually from an alternatingcurrent line through a transformer 20 stepping down the voltage toapproximately 6 volts. The alternating current as applied at 110 'voltsto the plate or control circuit 2| is rectied by the detector tube andused to energize an electromagnetic control device. 'Ihe change in theoutput power upon the reception of a signal is suflicient to'operatesuch a control device. As shown, the plate circuit 2| has interposedtherein a magnet 22 'having an 'armature 23 operating in response to thereceived signal.

24 is a grid condenser and 25 a variable condenser. The wave trainsconstituting the impulses of the transmitted signal, affect the grid inthe well known manner, producing negative y the plate current flowingthrough the relay coil- 22 energizes the relay. On the other hand, whena signal is being received, a reduction in the plate current occurs,de-energizing the relay and permitting movement of the armature 23 bythe spring 32.

In carrying out my invention, the operation of the relay under thecontrol of the received signal is utilized first, to initiate theoperation of a control device governing the actuation of the main motorswtich of the door operator, and then to insure continued operation ofthe control device through a complete cycle. To effectpproper operationof the relay to produce this result, the signal must be composed ofunits of different kinds, viz., impulse and space units, and these unitsmust also occur in proper timed relation in the control cycle.

'I'he control device in the present instance comprises a shaft 33 havinga series of cams thereon.

Y 'Ihis shaft is driven through the medium of a suitable gear train -34by an electric motor having a rotary drive shaft. Preferably, I employ asmall shadingring induction motor 35 having an energizing winding 36.Thus the driving means is of such character as to be operative uponcontinuous energization of the motor from` a local source of current asdistinguished from an interrupted energization as in the case ofordinary stepping magnets directly responsive to a succession oftransmitted impulses.

Energization of the motor 35 to start the cam shaft through an operatingcycle is effected by the relay 22 under the control of the incomingsignal. As herein shown, the cycle is initiated by the armature 23 andits spring 32 4as an incident to the reduction of the current in theplate circuit following the receipt of an initial impulse unit. In suchmovement, the armature 23 'closes a switch 31 the movable contact ofwhich is carried by the pivoted armature support and is electricallyconnected by conductors 29 and 30 with a conductor 2|P forming part ofthe control circuit 2| and connected to the line conductor 21. 'Ihestationary contact of this switch 31 is forme by an adjustable screw 38.

Said switch 31, hereinafter referred to as the primary relay switch,acts jointly with a switch 39 controlled by a cam 40 on the cam shaft 33to energize the motor 35 and initiate the cycle. As shown, the cam 40has a single lobe acting in the normal or rest position of the cam shaftto maintain the switch 39 closed. Of this switch` the stationary contact4| is connected by a conductor 42 with the stationary contact 38 of theprimary relay switch 31, and the movable contact 43 of the switch 39 iselectrically connected to a conductor bar 44 from which a conductor 45leads to the motor energizing winding 36. The opposite end of thewinding 36 is connected by a conductor 46 to the line conductor 28. Itwill be seen that the switch 39 constitutes a starting switch forinitiating the operation 'of the cam shaft 33 under the control of theprimary relay switch 31 operating in response to an initial impulse unitof the received signal.

The cycle of operation of the present motor driven control device may beconsidered as being divided into two parts or movements, one initiatedby the joint action of the switches 31 and 39, and a .second or finalmovement occurring as a continuation of the first movement provided theincoming signal is of a predetermined character. Accordingly, I providemeans operating to cause the cam shaft 33 to revolve, when once started,

lthrough'one-half revolution, and then to interrupt such movement unlessthe interrupting means is renderedV ineffective by the receipt of asignal unit of a certain kind. In the latter event, the operation of thecam shaft is continued for the remainder of the cycle.

The means for insuring at least the first portion ofthe movement of thecam shaft comprises in the present instance, a cam 41 having twodiametrically opposed notches 48 and controlling the operation of aswitch 49 independently of the relay 22. The movable contact of thisswitch 49 is connected to the bar 44 electrically connected by theconductor 45 with one end of the motor winding 36, and the stationarycontact of said switch 49 is connected by a conductor 50 and theconductors 3|] and 2| to the `line conductor 21. In the initial or restposition of the cam shaft, the switch 49 is open, but after the camshaft is started by the joint action of the switches 31 and 39, theswitch 49 is closed by the cam 41, so that the shaft 33 will revolve atleast through one-half revolution or until the opposite notch 48 of thecam 41 permits the running switch 49 to open.

The ability of the switch 49 to interrupt the rotation of the cam shaftafter the first movement thereof is dependent upon a variation in thetransmitted signal and, in the present instance, upon the occurrence ofa space unit controlling the operation of the relay 22 in advance of theopening of the switch'49. Such space unit is rendered effective throughthe conjoint operation of the relay and a third switch controlled by thecam shaft to continue the movement thereof through a complete cycle.Thus, I provide a secondary relay switch 52 arranged to be closed by therelay armature 23 in response to the receiptq of a space signal unit andan auxiliary running switch 53 in series with the switch 52 and arrangedfor actuation by a cam 54 on the cam shaft.

The movable contact of the auxiliary running switch 53 is electricallyconnected with the -motor as in the case of the switches 49 and 39, andthe stationary contact thereof is connected by a conductor 53B with thestationary contact of the secondary relay switch 52, mounted on asuitable bracket 55. The relay armature carries the movable contact ofthe latter switch.

armature and close the relay switch 52. If, therefore, the auxiliaryrunning switch 53 has at this time been closed, the circuit to the motoris completed. The cam 54 is,\of course, designed to hold the switch 53closed long enough to maintain the motor energized until the control ofthe motor is restored to the main running switch 49, it being observedthat the switch 49 is opened only momentarily at the end of one-halfVrevolution of the cam shaft.

'The initiation of a door operating cycle is under the control of thetiming device during the latter portion of its complete operating cycle,and such operation of the door operator is also made dependent upon thecharacter of the received signal. To this end, I provide a switch 51arranged to be closed by a cam 58 `on thesliaft 33 near the end of thecomplete control cycle. This switch 51 operates in conjunction with theprimary relay switch 31 to control the energizaton of a magnet Sarranged to close the main motor switch ii in any suitable way as, forexample, that shown in the said Colman patent! Said magnet 59 may beenergized from the door operator circuit which is connected with themain supply line i3 through the medium of the reversing switch of theoperator 6 and the normally closed field switch of the motor Ill, theother end of the magnet coil being connected by a conductor 60 with themovable contact of the switch 51. The stationary contact of this latterswitch is connected by a conductor 6l to the stationary contact 38 ofthe primary relay switch 31, so that when the latter.switch is closed,the above described circuit for relay 59 is extended by way ofconductors 29, 3D, 2ia and 21 to conductor I2 of the power line.Accordingly, operation of the main motor control switch Il is dependentupon the simultaneous closure oi the primary relay switch 31 and thecam-actuated switch 51, the

erator, actuatethe transmitter. switch 9, first to close the same, thento open the same, and nally to close the switch, the opening and finalclosing operations of the switch 9 to be performed in timed relation tothe operation of the main running switch 49 by its cam 41 and to theoperation of the door control switch 51 by its cam 58, as

will be hereinafter more particularly set forth, in`

connection with the time chart (Fig. 2).

In the preferred embodiment, a special-mechanically actuated griddischarge device is employed in connection with the radio receivercircuit for the purpose of conditioning the detector tube and the relaycontrolled thereby, so as to insure proper operation of the relayarmature 23 in response to the received signal units. This dischargedevice comprises a switch 62 arranged for actuation by a cani 63 on theshaft` 33 and having a stationary contact connected by conductors 63 and63' with the grounded side of the tube filament i9, and a movablecontact con-l nected by conductors 65 and 65a with the grid.' The cam 63has two diametrically opposed lobes 'operable to close the switch 62 andthereby permit discharge of the grid rst, after the receipt of the firstsignal unit, and again after the receipt of the third signal unit.' Inthe ilrst 1nstance, such discharge of the grid insures prompt7restoration of the plate current inthe relay conthe control cycle,operates to condition the tube for the reception of the first-impulseunit of the next signal, so that immediately upon the termination of onesignal, another Vsignal may, if desired, be transmitted and received.

`The'use of a mechanically operating grid discharge device is preferredfor the reason that it effects a rapid restoration of the detectortubeafter each impulse unit is received. If desired, however, an ordinarygrid leak may be used in addition to such a mechanical device, and Ihave shown in broken lines in Fig. 3 a grid leak 69 connected in anordinary way. If such a grid leak is used, the length or duration of thefirst signal impulse is not important. Thus itis only necessary that thefirst impulse unit be interrupted so that a space unit will occur andthus permit of closure of the secondary relay switch 52 for cooperationwith the auxiliary running switch 53 to complete the cycle, and that asecond .impulse unit occur to eiect a closure of the primary relayswitch 31 in proper'timed relation to the door control `switch 51. Thus,in this instance, a greater latitude is allowed the operator to effectthel desired control.

Referring now to the time chart (Fig. 2), the operation will besummarized and the sequence which permits of the actuation of thearmature' 23 by its spring 32. The primary relay switch 31 is thusclosed, and this switch acting jointly with the closed starting switch39 initiates a.y control cycle. In the present instance a completecontrol cycle is one complete revolution of the cam shaft. Shortly aftersuch initiation of the control cycle, the main running switch 49 isclosed by its cam 41 as indicated at a in the `time chart,

and as soon as this switch k49 has been closed, the starting switch 39is opened as indicated at b. Thus, the control device is started throughits rst half cycle. under the control of the first or impulse unit ofthe signal.

\ particularly set forth in connection with the pre-v The continuationof the control device through the second portion of its cycle requiresthe terterminated well in advance of the closure of the auxiliaryrunning switch 53 at d, as for example at e, corresponding in time tothe closing of the grid discharge switch 62 lat point f through theoperation of a cam 63. In any event the first impulse must be terminatedsomewhat in advance of the point g, when the grid discharge switchopens, to insure that the latter switch shall be held closed long enough-to effect a complete discharge of the grid of the tube i6.

Upon such discharge of the grid the plate current in the control circuitis promptly restored, so that the relay 22 becomes energized to effectclosure of the secondary relay switch 52, while the auxiliary runningswitch 53 is closed at d for cooperation with the switch 52 incontinuing the energization of the motor` Consequently,the subsequentopening of the main running switch at c is ineffective to stop thecontrol motor so as to interrupt the cycle at the end of its firstmovement. The auxiliary running switch 53 remains closed until point hsuiiiciently subsequent to the closure of the main running switch 49 atpoint i to insure transfer of control from one switch to the other. Onthe other hand it will be understood that if an impulse unit should bereceived at any point subsequent to the point g and in advance of thepoint i, the secondary relay switch will be prevented from closing andtherefore the driving motor will be stopped in an intermediate position.

Assuming that a complete cycle of the control device has been assured,energlzation of the main motor switch Il to initiate operation of thedoor' operator, is still dependent upon the proper transmission of animpulse unit constituting the third unit of the signal. The grid or tubehaving been discharged as above set forth, this third or impulse unitmust be received in proper timed relation to the actuation of the doorcontrol switch 51 by its cam 58. As shown, such closure of the doorcontrol switch 51 occurs at point j as shown in the time chart, and inorder that the relay switch 31 will have been closed in advance of theclosure of said switch 51, the third signal unit, while indicated on thechart as commencing substantially at k, must be received between thelpoints i and l. If received before point i, it will prevent closure ofthe secondary relay switch 52; and if received subsequent to point l,rthe door control switch will have opened. As shown on the chart, thedoor control switch 51 remains closed for a short time, between points jand ld; and th`e third signal unit is shown as terminating at 1n,although it may be continued somewhat beyond this point as willpresently appear.

To condition the tube for the immediate reception of the first impulseunit of a succeeding signal, should that be desirable, the griddischarge switch 62 is again closed at n. and again opened at o just inadvance of the termination of the cycle. Similarly, the starting switch39 is closed at p and the main running switch 49 opened at q preparatoryfor the next cycle.

ya properv control cycle requires that the operator send first, animpulse unitterminating before point a; second, a space unit betweenpoints g andi; and third an impulse unit between points i and l.lMoreover, the third vunit must be terminated in advance of the point oto avoid initiation of another control cycle.

It will be observed that by the arrangement thus set forth, the operatorof the vehicle may by a proper timing of the operation of the manualtransmitting switch 9, initiate from a remote point the operation of thepower driven 4door operator, it merely being necessary that the operatorcause the switch 9 to'be open for the transmission of a space signalunit in proper timed relation to the mechanical operation of the mainand auxiliary running switches. Exact timing is, however, not necessary,and the operation of the control device at true synchronous speed isalso not required. In other words, the method of control employed issufciently flexible to permit Aof slight variation in timing, both in sofar as the human element is concerned and also, with regard to themechanical operation. Should the operator fail to open the switch 9within the time allotted, the operating cycle will be interrupted at theend of the first movement through the operation of the main runningswitch 49. In this event, the

' means for continuing the cycle, namely, the

auxiliary running switch 53 and the secondary relay switch 52, will berendered ineffective because of the failure of the relay 22 to close theswitch 52. Similarly, in the event of initiation of the cycle by asingle electric impulse, such as may occur in a thunder storm, the cyclewill be interrupted at the end of the first movement.

a first or impulse unit be terminated properly Y so as to effect acompletion of the control cycle, initiation of the door operating cycleis still dependent upon the transmission of an impulse to constitute thethird unit of the signal; and that this impulse must be transmitted soas to occur in timed relation to the closure of the door co'ntrol switch51 by the cam 58. Therefore, the transmission of a short impulseconstituting the ,first unit of the signal followed by a space unitcontinued throughout the remainder of the cycle, would be ineffective toinitiate a door operation.

In the event that a grid leak 66 is used in adldition to the mechanicalgrid discharge, the first impulse unit of the signal maybe continued, asfor example to point r, reference being made to the time chart in whichthis modified signal is shown in broken lines. Thereafter, theoccurrence of a short space unit in the signal will permit thecontinuation of the operating cycle througha closure of the secondarycontrol switch 52. Finally, transmission of a third unit in the form ofan impulse occurring while the door control switch 51 is closed, willinitiate the operation of the door motor. It will be seen, however, thatgreater care is necessary to be exercised on the part of the operatorwhere a mechanical `grid discharge is used, and therefore, it ispossible with this latter construction to obaoeaseo tain a higher degreeof secrecy so as tdlesser the possibility of unintended or accidentaloperation.

AI claim as my invention:

-1. A control mechanism having a signal rsponsive receiver, a partto beoperated, a primary control lmeans differentially operable in responseto a received signal having units of diiferent -kix/ids, and acyclically operable secondary `control means cooperating with theprimary control means only upon the receipt of a preconcerted signalcombination to initiate the operation of said part, vsaid secondarycontrol means including an electric motor having a control circuit, aplurality of switches actuated by said motor and cooperating with saidprimary con trol means at different points in,y the operating cycle ofthe secondary control means to maintain said control circuit closedduringa predetermined operating cycle, and -an additional switchactuated by said motor and cooperating with said primary control meansat a point in said operating cycle subsequent to said first mentionedpoints to initiate the operation oi saidv ing cycle and subsequently inresponse lto va different kind of signal unit to complete said operatingcycle, and means actuated at a predetermined point in the cyclesubsequent to the receipt of said diierent signal unit to `cooperatewith said signal responsive means in .initiating the operation of saidpart. u

3. remote control system having in combination with a part to becontrolled, means for transmitting a signal composed of impulse andspace units, a control device to be operated through a predeterminedcycle, driving means for said device including a rotary electric motor,and means responsive to a transmitted signal of a preconcerted characteradapted to cooperate with said control device to control theenergization of said motor`,'saidsignal responsive means being operativeduring an intermediate portion of the cycle only under the control of aspace unit to maintain said motor energized, and said control devicehaving means cooperating with said signal responsive means in responseto a'signal unit'of a predetermined character occurring subsequent tothe movement of said device past said predetermined point to vgovernoperation of said part to be controlled. A

fi. A remote control system having in combination with a part to becontrolled, means for transmitting a signal combination composed of:units of different kinds, a control device to be operated through apredetermined cycle, driving means for said device including a rotaryelectric motor, and

, means responsive to a transmitted signal of a preconcerted characterand adapted to cooperate with said control device to effectmovement ofsaid `device through said cycle,y said signal resp'onsive means beingoperative under the control of a signal unit oifa predeterminedcharacter only to maintain said motor energized at an intermediate pointin the cycle; and said. conltrol device andrsignal responsive meansbeing further operative under the control of a signal unit of apredetermined character occurring subsequently to the movement ofv saiddevice past said predetermined point to govern the operation of saidpart to be controlled.

5. A remote control system for effecting a control operation in responseto a particular signal, said system having, in combination, means fortransmitting a signal composed of units of different kinds occurring insuccession, a control device to be operated throughl a predeterminedcycle, driving means for said device including an electric motor, andmeans responsive to a .transmitted signalof a lpreconcerted characteradapted tol cooperate with said control device to effect movementthereof through said cycle,

said control devicevincluding two motor control switches and a thirdswitch, and said Isignal responsive means being adapted to cooperatewith said two motor control switches at different times in response tosignal units of different kinds to govern the energization of saidmotor, and to cooperate With'said third switch in response to a signalunit received subsequent to the signal units governing the energizationofthe motor to eiiecta control operation.

6. A remote control system having, in combination with a part to becontrolled, `means for transmitting 'a signal composed of units ofdifferent kinds, atcontrol device to be operated through a predeterminedcycle, driving means for said device including a rotary electric motor,and means responsive to one unit of a transmitted signal of apreconcerted character adapted to cooperate with said control device toinitiate movement thereof through a part of said cycle and responsiveto' another unit 'of said signal to initiate movement of the devicethrough the remainder of said cycle, said control device including meansoperative in conjunction with said signal responsive means in the latterpart of the cycle to govern the operation of said part to be controlled.

7. A remote' control system for effecting the operation of a motordriven operator, said system having a motor driven control means,including an electric motor and a control `element vto be driven therebythrough a predetermined cycle, means for initiating the energization ofsaid motor from a normal rest position including a signal responsivedevice responsive to one kind oi signal unit, other means operable bysaid control element in the initial portion of its movement to continuethe energization of said`motor through a predetermined distance and thento interrupt such energization, means including a second signalresponsive device responsive to a .different kind of signal unit torender the'last mentioned means ineffective to interrupt theenergization of said motor, and means actuated by .said control elementin the latter part of its cycle 'operative in cooperation with saidfirst signal responsive device for initiating the operation of saidpower driven operator.

8. A remote control system having, in combination, a control device tobe operated through a predetermined cycle, means responsive to a signalcomposed of impulse and space vunits including a control circuit havingan electromagnet therein and a detector tube having a grid tending toretain the-characteroi .an impulse unit of the received signal, saidsignal responsive means being arranged to cooperate with said controldevice in response to signal units of diierent kinds to effect movementof the device through said cycle, and means operative after the receiptof an impulse unit to discharge the grid of said tube and to conditionthe magnet for operation only under the control of a space unitfollowing the impulse unit within a predetermined interval.

9. A remote control system having, in combination, a control device tobe operated through a predetermined cycle, means responsive to a signalcomposed of impulse and space units including a controlling circuithaving an electromagnet therein and a detector tube having a gridtending to retain the character of an impulse unit of the receivedsignal, means for driving said control device including an electricmotor, switch means for controlling the energization 0f said motorduring said cycle including a pair of switches controlled by said magnetin response to an impulse unit and a succeeding space unit,respectively, and a pair of switches controlled by said devicecooperating successively with said first mentioned switches andoperative respectively to initiate and maintain energization of saidmotor; and means for discharging the grid of said tube after the receiptof the impulse unit to condition the magnet for operation only under`the control of the succeeding space unit received within apredetermined interval after said impulse unit.

10. A remote control system having a. control mechanism including anelectric motor having a rotary armature, a control device having a xeddriving connection with said armature and adapted to be driven in onedirection only from the beginning of one control cycle to the normalstarting position of the next control cycle, a part to be operated, andsignal responsive means cooperating with said device at different pointsin said cycle to control energization oi said motor and at a point insai'd cycle subsequent to said rst mentioned points for initiating theoperation of said part to be controlled.

' DUNCAN J. STEWART.

